Do humans with the ancestral hair-type also have pediculus humanus capitis lice? Pubic hair lice, Pthirus pubis, are adapted morphologically to cling onto coarse body hair, and originates from Pthirus gorillae via a host switch 3.3 Ma1. Pthirus pubis is also, at times, found at the eyelashes of infants.
The ancestral hair type is coarser than the derived, longer and thinner hair type. Is it parasitised by pediculus humanus capitis, or, by a lice that is adapted to cling onto the coarser hair, possibly related to Pthirus pubis?
The ancestral hair form is frizzier and much shorter. It survives in sub-Saharan Africans and in other groups whose ancestors never left the tropics, notably the Andamanese, the Semang, the Aeta, and the natives of Australia and Papua New Guinea. The latter groups are descended from humans who spread out of Africa along the southern route into South and Southeast Asia.2
Reed, D. L., Light, J. E., Allen, J. M., & Kirchman, J. J. (2007). Pair of lice lost or parasites regained: the evolutionary history of anthropoid primate lice. BMC Biology, 5(1), 7. doi:10.1186/1741-7007-5-7